Sealable attachment of endovascular stent to graft

ABSTRACT

An endovascular prosthesis of the present invention includes an expandable stent and a means for sealably attaching a tubular graft to the stent within the stent&#39;s lumen. The means of sealably attaching a graft includes membranes, foams, polymeric materials and combinations thereof. Additionally, the present invention includes methods of forming an endovascular prosthesis and methods of implanting an endovascular prosthesis within a vessel to provide sealable securement of a tubular graft within the stent&#39;s lumen.

FIELD OF THE INVENTION

[0001] The present invention relates to an endovascular prosthesis forintraluminal delivery, and a method of implanting the endovascularprosthesis for repairing an aorta. More particularly, the presentinvention relates to endovascular prosthesis including a stent and ameans for sealably attaching a graft thereto for use in a blood vesselor a bifurcated system, such as an abdominal aortic artery where itbifurcates to the common iliac arteries.

BACKGROUND OF THE INVENTION

[0002] An abdominal aortic aneurysm (“AAA”) is an abnormal dilation ofthe arterial wall of the aorta in the region of the aorta that passesthrough the abdominal cavity. The condition most commonly results fromatherosclerotic disease. Abdominal aortic aneurysms are typicallydissecting aneurysms, which are aneurysms that are formed when there isa tear or fissure in the arterial lining or wall through which blood isforced and eventually clots, forming a thrombosis which swells andweakens the vessel. Abdominal aortic aneurysms typically do not causepain and are easily detected by physical examination. The aneurysm mayrupture if it is not detected and treated, causing massive hemorrhagingwhich is likely to be fatal to the patient.

[0003] Treatment of AAAs typically comprises some form of arterialreconstructive surgery, commonly referred to as a “triple-A” procedure.One such method is bypass surgery, in which an incision is made into theabdominal cavity, the aorta is closed off above and below the site ofthe aneurysm, the aneurysm is resected, and a synthetic graft or tubesized to approximate the diameter of the normal aorta is sutured to thevessel to replace the aneurysm and to allow blood flow through the aortato be reestablished.

[0004] Many patients experiencing such AAAs, however, are over 65 yearsof age and often have other chronic illnesses which increase the risk ofpre-operative or post-operative complications. Thus, such patients arenot ideal candidates for triple-A procedures. Further, this procedure isgenerally not performed successfully once an aneurysm has ruptured dueto the extensiveness of the surgery and the time required to prepare apatient for surgery. The mortality rate for patient experiencing suchruptured aneurysms is over 65%.

[0005] As a result of the aforementioned disadvantages to conventionalsurgical methods, minimally invasive techniques have been developed forthe repair of AAAs. Such methods involve placement of a stent-graft atthe site of the aneurysm by a catheter, known as an introducer, whichserves as a deployment device. The stent-graft and its deployment systemare typically introduced into the blood stream percutaneously andnegotiated by means of a guidewire to the site of the aneurysm where thestent is caused to be radially expanded. Such procedures are desirableas they can be performed using local anesthesia and do not expose thepatient to many of the same risks associated with triple-A procedures.But the bifurcated structure and environment of the abdominal aortic andthe technology of the prior art stent-grafts continue to be plagued withissues associated with long term stability.

[0006] In such minimally invasive repair procedures, the bifurcatedstructure of the abdominal aortic arch necessitates the use of auniquely-structured bifurcated stent-graft. Typically, aneurysms,occlusions or stenoses will occur at the location where the aortic archbifurcates into the iliac arteries and may also occur at the iliacarteries. The in situ positioning of stent-grafts in this area is moredifficult than the positioning of such devices in the lumen ofnon-bifurcated vessels. As both limbs of a bifurcated stent-graft areinserted and advanced through a single branch of the femoral arterialsystem, one of the limbs of the stent-graft must ultimately be pulled ordrawn into the contralateral branch so that the stent-graft is suitablypositioned across both the aortic aneurysm and the associated commoniliac aneurysms to supply circulation to each of the lower limbs.

[0007] Bifurcated stent-grafts are frequently too bulky to advancethrough a single iliac artery, particularly in view of the fact that thelimb for the contralateral branch of the stent-graft must be insertedtogether with the limb of the ipsilateral branch. Additionally, caremust be taken to not twist or kink the stent-graft as it is placed inthe contralateral artery. The caudal portion of the graft must notstretch across the mouth of the internal iliac artery which would resultin inadvertent occlusion of that artery. The procedure of drawing onelimb of the stent-graft from one femoral artery to the contralateralfemoral artery requires placement of a cross-femoral catheter using aclosable wire basket prior to insertion of the stent-graft.

[0008] This procedure requires significant and skillful wire cathetermanipulation, frequently within the aneurysmal cavity. As such, caremust be taken to avoid disturbing or dislodging thrombic or embolicmaterial from within the aneurysmal sac. Additional factors such as thesevere tortuosity of the iliac arteries and the marked angulation of theaortoiliac junction resulting from the tendency of the abdominal aorticartery to extend caudally during aneurysm formation combine to makedeployment of endoluminal bifurcated grafts time consuming and atincreased risk of procedural complications and failure.

[0009] To overcome the aforementioned risks associated with the use ofone-piece stent-grafts in the repair of aneurysms occurring inbifurcated vessels, two component bifurcated designs have been developedwhich may be assembled in situ. The first component consists of theupper trunk, which is positioned just below the renals, a stump, and aniliac limb. The second component is then deployed into the stump,connecting the device to the contralateral iliac limb. These deviceshave had a number of issues, which include fabric wear, kinking, andendoleaks at the upper neck and at the stump junction; in addition, somehave proven to be difficult to manufacture, not secure to vessel wall,or difficult to assemble in situ.

[0010] The main reason for lack of success with endoluminal repairfocuses around the fact that the vascular system in general, and moreapparent in an aneurysm sac is the morphology continues to change. Themorphological environment leads to unexpected and unanticipated stresswhich is placed on the stent-grafts used to treat the disease. Suchwearing and endoleaking necessitates the repair of these devices,requiring additional surgical procedures which may include replacementof the device. Consequently, there is a continuing need for thedevelopment of stents with attached grafts and techniques useful for therepair of aneurysms in general, and AAAs.

SUMMARY OF THE INVENTION

[0011] In view of the foregoing, it is an object of the presentinvention to provide an endovascular prosthesis and method of implantingthe prosthesis into a vessel that provides a means for sealablyattaching a tubular graft within the endovascular prosthesis.Additionally, the present invention provides for a prosthesis that isflexible and durable to adjust to the morphological environment and isable to assemble in situ.

[0012] The present invention includes an endovascular prosthesisincluding an expandable stent having an inner lumen, and a means forsealably attaching a tubular graft within the lumen of the stent. Themeans of sealably attaching a graft includes membranes, foams, polymericmaterials and combinations thereof.

[0013] Another embodiment of the present invention, there is provided anendovascular prosthesis including an expandable stent and a membranesupported by the stent and extending across the lumen. The membranefurther including a graft receiving member for sealably receiving atleast one tubular graft therethrough.

[0014] The present invention further provides an endovascular prosthesisas above-described and the membrane further including anelectrostatically spun material having a graft receiving opening forsealably receiving at least one tubular graft therethrough.

[0015] An embodiment of the present invention, there is provided abifurcated endovascular prosthesis including a first prostheticcomponent and a second component. The first component is similar tothose described-above including a stent, a membrane extendingtransversely across the inner lumen of the stent and attached thereto.The membrane additionally having an opening. The second prostheticcomponent being extended through the opening in a substantially fluidtight seal. The second component further including one or more grafts.

[0016] A further embodiment of the present invention, there is provideda multi-component endovascular prosthetic system including twoprosthesis and a tubular graft. Each prosthesis including an expandablestent and a membrane extending transversely across the inner lumen andattached to the stent. Each membrane further having a graft receivingopening. The tubular graft being extended sealably through a graftreceiving opening of each prosthesis for directing fluid through thetubular graft.

[0017] Another embodiment of the present invention, there is provided anendovascular prosthesis including a stent having an inner lumen, adistal end and a proximal end, the distal end having an opening, and theproximal end having two openings opposing the distal opening; and apuncturable membrane extending across each of the proximal end openings.

[0018] Another aspect of the present invention, there is provided anendovascular prosthesis including an expandable stent, a first graft anda second graft. The expandable stent has a distal end and a proximalend, and an opening extending therethrough. The first graft beingattached to the distal end of the stent within the opening, and havingan inner lumen extending therethrough. The second graft being attachedto the proximal end of the stent within the opening and spaced from thefirst graft. The second graft having at least two inner lumens extendingtherethrough and a membrane extending transversely across each of theinner lumens of the second graft.

[0019] Another embodiment of the present invention, there is provided anendovascular prosthetic assembly including an expandable stent and atubular graft inserted within the inner lumen of the stent. The grafthaving an expanded foam attached to the exterior surface of the graft.The expandable foam sealably securing the tubular graft to the stent.

[0020] One aspect of the present invention, there is provided a kit ofparts for assembly into an endovascular prosthetic system. The kitincluding an expandable stent for insertion into a body endovascularly;a tubular graft adapted to be inserted within the stent, the tubulargraft having an interior surface for body fluid flow and an exteriorsurface; and an expandable foam on the exterior surface of the tubulargraft. The expandable foam being adapted to expand within the stent tosealably secure the tubular graft to the stent.

[0021] A further embodiment of the present invention, there is providedan endovascular prosthetic assembly including a stent, a tubular graftextending into the stent and a polymeric material sealably supportingthe tubular graft to the stent.

[0022] Another aspect of the present invention there is provided, a kitof parts for assembly into an endovascular prosthetic system. The kitincluding a stent having a primary reactive material being disposed onthe inner surface of the stent; a tubular graft adapted to extend withinthe inner lumen, the graft having the primary material being disposed onthe exterior surface; and a secondary material reactive with the primarymaterial. The second material being adapted to be applied to the primarymaterial upon insertion of the graft within the inner lumen, thesecondary material being reactive with the primary material to form aseal between the graft and the stent.

[0023] A further aspect of the present invention there is providedmethods of forming and methods of implanting the various endovascularprosthesis of the present invention within a vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1 is an enlarged plan view of the endovascular prosthesis ofthe present invention including a stent and attached membrane havinggraft receiving members.

[0025]FIG. 2 is a plan view of an endovascular prosthesis of FIG. 1implanted in abdominal aorta.

[0026]FIG. 3 is a top view of the endovascular prosthesis of FIG. 1showing the graft receiving members.

[0027]FIG. 4 shows the endovascular prosthesis of FIG. 1 furtherincluding grafts.

[0028]FIG. 5 is a top view of the endovascular prosthesis of FIG. 3including grafts therethrough.

[0029]FIG. 6 shows the bifurcated endovascular prosthesis of FIG. 2including a branched graft.

[0030]FIG. 7 shows the endovascular prosthesis of FIG. 2 includingtubular prosthesis for a bifurcated system.

[0031]FIG. 8 shows the endovascular prosthesis of FIG. 7 showing adeployment of tubular prosthesis for a bifurcated system.

[0032]FIG. 9 is a plan view of an endovascular prosthesis of the presentinvention showing a stent and a membrane.

[0033]FIG. 10 shows the endovascular prosthesis of FIG. 9 furtherincluding tubular graft.

[0034]FIG. 11 shows a multi-component endovascular prosthetic system ofthe present invention.

[0035]FIG. 12 shows an endovascular prosthesis of the present inventioncombined with tubular grafts.

[0036]FIG. 13 is an enlarged plan view of an endovascular prosthesis ofFIG. 12 including a stent and attached membrane.

[0037]FIG. 14 is a plan view of an endovascular prosthesis of thepresent invention showing a stent, grafts and membranes in combinationwith tubular grafts.

[0038]FIG. 15 is a plan view of the endovascular prosthesis system ofthe present invention showing the expandable foam in the expanded state.

[0039]FIG. 16 shows the endovascular prosthetic assembly of FIG. 15showing the expandable foam.

[0040]FIG. 17 is a plan view of an endovascular prosthesis of thepresent invention showing a stent having an attached membrane incombination with an expandable foam.

[0041]FIG. 18 is a plan view of an endovascular prosthetic system of thepresent invention showing a polymeric material sealably supporting atubular graft to a stent.

[0042]FIG. 19 shows the endovascular prosthetic system of FIG. 18showing a primary reactive material on a graft and stent.

[0043]FIG. 20 is a plan view of an endovascular prosthesis of thepresent invention showing primary material on the membrane and grafts.

[0044]FIG. 21 shows the endovascular prosthesis of FIG. 20 showing thepolymeric material sealably securing the tubular graft to a membrane.

DETAILED DESCRIPTION OF THE INVENTION

[0045] The present invention relates to an endovascular prosthesis forintraluminal delivery, as shown in FIGS. 1-21. The prosthesis isparticularly suited for use as a vascular prosthesis. The prosthesis ofthe present invention overcomes the aforementioned problems of the priorart including leaking and wearing between a tubular prosthesis and astent. Additionally, the prosthesis of the present invention providesflexibility to adapt to the morphology of the vascular environment. Theprosthesis of the present invention includes minimal components toprovide for a simple assembly in situ.

[0046] One embodiment of the present invention is a prosthesis 1 asshown in FIG. 1-3. The prosthesis 1 is a generally tubular structurewhich includes a stent 2 and a membrane 3.

[0047] The stent 2 of the present invention is similar to those known inthe art. The stent 2 can be open-celled or porous which is in directcontact with the aortic wall. This permits ingrowth of cells for thestabilization of implanted endoprosthesis, and device fixation. Thestent may further be coated with various materials as known in the artto encourage cell growth therethrough. In addition, the stent 2 mayincorporate a covering, or a graft composite (not shown) to preventblood flow therethrough. The stent 2 may be covered or coated on thestent's exterior, interior or both depending on the application.

[0048] As is known in the art, a stent has two diameters, the compresseddiameter and the expanded diameter wherein the compressed diameter issubstantially smaller than the expanded diameter. The compresseddiameter of a stent varies depending on the materials of constructionand structure of a stent. In general, the compressed diameter must besmall enough to allow for implantation through the vasculature via aminimally invasive deployment system (not shown). The expanded diameterneeds to be substantially the same diameter-as the vasculature in whichit is to replace or repair. The expanded diameter needs to be largeenough to allow a stent to sufficiently secure to the aortic wallwithout acting as a driving force to expand or dilate the vessel.

[0049] Various stent types and stent constructions may be employed inthe invention. Stents may be capable of radially contracting, as well,and in this sense can best be described as radially distensible,deformable or conformable. Stents may be balloon expandable orself-expandable. Balloon expanding stents include those that areradially expanded by an applied force. Self-expanding stents includethose that have a spring-like action which causes the stent to radiallyexpand, or stents which expand due to the pre-set memory properties ofthe stent material for a particular configuration at a certaintemperature range. Nitinol is one material which has the ability toperform well while both in spring-like elastic mode, as well as in amemory mode based on temperature. Other materials are of coursecontemplated, such as stainless steel, tantalum, platinum, gold,titanium and other bicompatible metals, as well as shape memory polymersor polymeric based stents, or indeed composites of the aforementioned.

[0050] The configuration of a stent may also be chosen from a host ofgeometries. For example, wire stents can be fastened into a continuoushelical pattern, with or without a wave-like or zig-zag in the wire, toform a radially deformable stent. Individual rings or circular memberscan be linked together such as by struts, sutures, welding, interlacingor locking of the rings to form a tubular stent structure. Tubularstents useful in the present invention also include those formed byetching or cutting a pattern from a tube. Such stents are often referredto as slotted stents. Furthermore, stents may be formed by etching apattern into a material or mold and depositing stent material in thepattern, such as by chemical vapor deposition or the like.

[0051] As shown in FIGS. 1 and 2, stent 2 has a pair of spaced apartends, a distal end 4, and a proximal end 5, and a tubular wall structuretherebetween. The tubular wall structure has an external surface and aninternal surface which defines the inner lumen 6 of stent 2. Themembrane 3 is supported by stent 2 and extends across the inner lumen 6of stent 2. The membrane 3 has one or more graft receiving members 7 forsealably receiving at least one tubular graft therethrough. The graftreceiving member 7 is defined as a weakened section, a slit, a hole, apenetrable material, a punchout, a puncture, a valve and the like.

[0052] Generally, membrane 3 is impermeable to blood, but the membranematerial can be permeable to blood and coated to be or becomeimpermeable in situ. Membrane 3 may be made from a variety of well knownmaterials, provided they have the requisite strength characteristics andbiocompatibility properties. Membrane 3 is made from a flexible andcompressible material. In addition, membrane 3 may be synthetic ornatural. Examples of such materials are polymers, elastomers, rubbers,waxes, silicone, parylene, polyurethane, vinyl polycaprolactone,(TEFLON) polytetrafluoroethylene, polypropylene, polyethylene, DACRON,allograph, zeno-graph material, latex, as well as composites of theaforementioned. Examples of commercially available materials areCorethane (Corvita); Carbothane (Thermedics); Silastic, Pellethane, andParylene (Specialty Coating Systems). The material can be extruded,knitted, woven, or electrostatically spun material.

[0053] Additionally, membrane 3 can be coated or impregnated withbio-erodible, biodegradable or degradable material such as polymers,albumin, collagen, heparin or similar coating material. The membranecould have a coating of a biologically inert material, such as PTFE, orporous polyurethane. The coating can be added to the membrane by methodsknown in the art such as dipping, spraying or vapor disposition on thematerial.

[0054] The thickness of membrane 3 can vary depending on the applicationand the material of construction of membrane 3. Generally, the thicknessof the membrane is less than the distance between distal end 4 andproximal end 5 of the stent 2. Therefore, some part of stent 2 extendsabove and/or below membrane 3. For example, in a vascular applicationmembrane 3 can range from 0.001 mm-0.6 mm, preferably 0.1 mm-0.4 mm.

[0055] Membrane 3 may be a planar surface or a variety of shapesdepending on the application. Membrane 3 can be shaped to assist inbonding membrane 3 to stent 2 and/or to provide sealable securement of atubular graft to membrane 3. For example, FIG. 1 shows membrane 3 havinga peak formation 3 a and 3 b, having the graft receiving member locatedat the top of the peak formation 3 a and 3 b. The peak formation 3 a and3 b assist in sealing between a tubular graft and membrane 3 byproviding more surface area contact between the two surfaces, shown inFIG. 5 as peak formation 13 a and 13 b and tubular graft 18. Acup-shape, or sock-shape membrane assists in attaching the membranewithin the stent lumen by providing more surface area for the membraneto bond to a stent.

[0056]FIGS. 1 and 3 show membrane 3 attached to and supported by innerlumen 6 of the stent 2. Membrane 3 can be attached to stent 2 byadhesive bonding, such as silicone or polyurethane; mechanicalattachment, such as sutures or staples; thermal bonding, laminate; orchemical bonding. In addition, the inner surface of stent 2 may becoated with an elastomer or polymer and a solvent may be used to bondthe coated inner surface to the membrane. Membrane 3 can be positionedacross inner lumen 6 of stent 2 at any location along stent 2 such asacross the distal end 4, the proximal end 5 or there between of stent 2.

[0057] As shown in FIG. 1-3, the membrane 3 extends transversely acrossthe inner lumen of stent 2 with a peak formation 3 a and 3 b locatedcentrally in the membrane 3. A graft receiving member 7 is located atthe top of each peak formation 3 a and 3 b. FIG. 2 shows the peakformation 3 a and 3 b directed in the cephalic direction, but it can beappreciated that the peak formation 3 a and 3 b can be inverted suchthat the top of the peak is directed toward the caudal direction,depending on the desired application. In addition to assisting insealing a tubular graft to the membrane 3, the peak formation 3 a and 3b acts as a check valve allowing fluid to flow in one direction acrossmembrane 3, and closes upon no flow of fluid in that direction.Additionally, the peak formation 3 a and 3 b prevents back flow of fluidin the opposite direction through membrane 3.

[0058] The prosthesis of the present invention as described above may beused in combination with one or more grafts. As shown in FIGS. 4 and 5,prosthesis 10 is similar to prosthesis 1 of FIG. 1, further includinggraft 18 extending sealably through graft receiving member 17. Themembrane 13 material of the peak formation 13 a and 13 b conforms aroundgraft 18 and becomes coextensive with a portion of graft 18 securinggraft 18 in a sealable manner. The flow of blood through graft 18applies outward radial pressure to the graft 18 against membrane 13,more specifically peak formation 13 a and 13 b. Membrane 13 provides anopposing force against graft 18 provided by the membrane's 13 securementto stent 12 restricting its movement and, additionally, the restrictedaccess of the graft 18 through the graft receiving member 17 of membrane13. These opposing forces create a seal between graft 18 and membrane13. It can be appreciated that one or more peaks may be formed inmembrane 13 material depending on the application.

[0059] Any known graft material, or tubular prosthesis, and structuremay be used to form the graft of the present invention. The graftpreferably has generally a tubular configuration. The graft may be madefrom a variety of well known materials, provided they have the requisitestrength characteristics and biocompatibility properties. Examples ofsuch materials are polyester, polypropylene, polyethylene,polytetrafluoroethylene, expanded polytetrafluoroethylene andpolyurethane, DACRON, TEFLON (polytetrafluoroethylene), and PTFE coatedDACRON as well as composites of the aforementioned. The material can beextruded, woven or knitted, warp or weft knitted. The graft can also becoated or impregnated with a bio-erodible, or degradable material, suchas albumin, collagen, heparin or similar coating material. Additionally,the graft could have a coating of a biologically inert material, such asporous polyurethane.

[0060] In general, the diameter of graft 18 varies depending on theapplication but generally at least a portion of graft 18 (or grafts, ifmultiple grafts used) should be substantially the same diameter as thegraft receiving member 17. Generally, the diameter of graft 18 should belarge enough to allow for unobstructed blood flow and prevent retrogradepressure build-up in the blood flow while maintaining sufficienttraction against membrane 13 for long-term fixation. While cylindricaltubular configurations are shown, other tubular configurations may beemployed.

[0061] Another embodiment of the present invention is a bifurcatedprosthesis 20 as shown in FIG. 6. FIG. 6 shows a first prostheticcomponent 21 similar to the prosthesis 1 of FIG. 1 including anexpandable stent 22 and a membrane 23 extending transversely across theinner lumen of and attached to the stent 22. Membrane 23 has one or moregraft receiving openings 27 or members. The bifurcated prosthesis 20further includes a second component 26 including a branched graft 28. Inone embodiment branched graft 28 has an inverted “Y” shape having twoleg portions, 28 a and 28 b, converging into one trunk portion 28 c. Thetrunk portion 28 c extends into graft receiving member 27 of themembrane 17 creating a substantially fluid tight seal between the outersurface of graft 28 and membrane 23. The two leg portions, 28 a and 28b, extend into each iliac artery 8 (8 a and 8 b). The leg portions (28 aand 28 b) remain in place by the pressure from the blood flowingtherethrough and forcing the leg portions (28 a and 28 b) into eachiliac artery 8 (8 a and 8 b). Additional anchoring stents 24 and 25 canbe used in combination with the leg portions (28 a and 28 b), as shownin FIG. 6, to provide additional securement of graft 17 to the iliacartery wall.

[0062] Another bifurcated embodiment of the present invention is shownin FIG. 7 which is similar to the above described bifurcated prosthesis20 of FIG. 6 including a stent 32, a membrane 33 extending transverselyacross the inner lumen of stent 32, graft receiving members 37 andgrafts 38. However, the bifurcated prosthesis 30 of FIG. 7 includes twoseparate graft 38 (38 a and 38 b) instead of the branched graft 28 ofFIG. 6. As shown in FIG. 7, grafts 38 extends into separate graftreceiving members 37 (37 a and 37 b) and form a substantially fluidtight seal between grafts 38 and membrane 33. Additional anchoringstents 34 and 35 can be added for securing grafts 38 to the iliac vesselwall (8 a and 8 b).

[0063] Another embodiment of the present invention is shown in FIGS. 9and 10 which is similar to the prosthesis 1 of FIG. 1 including anexpandable stent 42 and a membrane 43 attached to stent 42 and extendingtransversely across the lumen of stent 42. Membrane 43 of FIG. 9includes electrostatically spun material. FIG. 9 shows electrostaticallyspun material formed into a planar disk shape instead of the peakformation of FIG. 1. The electrostatically spun material has a graftreceiving opening 47, similar to graft receiving member 7 of FIG. 1, forsealably receiving at least one tubular graft therethrough. It can beappreciated that a variety membrane 43 of shapes and locations on stent42 can be used depending on the application, as above-discussed.Generally, electrostatically spun material is similar to material knownin the art for vascular grafts. The spun structure of the membraneprovides a porous scaffolding structure for blood to clot within andprovide a sealable material. The basic process of electrospinning inwell known in the art. The process involves the introduction ofelectrostatic charge to a stream of polymer melt or solution in thepresence of a strong electric field. The predominant form of operationentails charge induction in the fluid through contact with a highvoltage electrode in a simple metal or glass capillary spinnerette. Acharge jet is produced which accelerates and thins in the electricfield, ultimately collecting on a grounded device, typically a plate orbelt. Under certain conditions of operation, the fluid jet becomesunstable before it reaches the collector. The onset of instability, withlow molecular weight fluids, typically results in a spray of small,charged droplets, in a process known as “electrospinning” permitting.Viscoelastic forces stabilize the jet, with polymeric fluids, permittingthe formation of small diameter, charged filaments that appear as an“envelope” or a cone dispersed fluid, and that solidify and deposit onthe collector in the form of a nonwoven fabric. Under these conditions,it is common to observe mean fiber diameters on the order of 0.1 μm,three orders of magnitude smaller than the diameter of the jet enteringthe unstable region (10-100 μm). The electrostatic spinning process isdescribed in U.S. Pat. No. 4,044,404 and U.S. Pat. No. 4,323,525, and ishereby incorporated herein by reference. Additionally, the material ispermeable. The pore size of the material will usually be between 0.001μand 500μ. In order for the material to be sufficiently porous to allowpenetration of cells into the surface layers, the average surface poredimension is preferred to be of the order of 5 to 25μ, more preferablybetween 7 and 15μ, although pore size in the bulk of the material mayaverage about 1μ. In addition, the membrane may be coated with amaterial to promote clotting, or provide a non-permeable material toprevent fluid flow, such as collagen, or an elastomer, such asCorethane. Additionally, prosthesis 40 can include multiple layers ofmaterials forming the membrane such as an electrospun layer over asilicon layer.

[0064] Prosthesis 40 can be used in combination with various grafts toprovide multi-component systems, bifurcated systems, stent-graftprosthesis and the like, as shown in FIG. 10. Prosthesis 40 used incombination with at least one tubular prosthesis 48 extending throughthe graft receiving opening 47 and sealably supporting the tubularprosthesis 48. Generally, the tubular prosthesis 48 includes a graftwhich is positioned through graft receiving opening 47 in a compressedstate. The graft 48 may vary in size and shape depending on the desiredapplication. For example, a portion of the graft 48 extending on eitherside of the graft receiving opening 47 may have a larger diameteropening than the portion extending through the graft receiving opening47 to provide for additional securement of the graft 48 to the membrane43. Once in place, the graft 48 is allowed to expand in the graftreceiving opening 47. The pressure from the blood through the graft 48secures the graft 48 to the electrostatically spun membrane, as similardescribed above in regards to prosthesis 1 of FIG. 1.

[0065] The above described prosthesis as shown in FIGS. 1-10 can beloaded into a delivery system for deployment within, a body lumen. Thedelivery system used is similar to those known in the art. Typically,the delivery system has an introductory device or sheath in which theprosthesis is compressed therein. Once the desired vascular site isreached, the sheath is removed, leaving the stent and attached membranelocated endoluminally. Additional components may be used in combinationwith the above deployed prosthesis such as a tubular graft. A tubulargraft is deployed after the initial prosthesis is deployed using thesame delivery device with an additional sheath or a separate device.

[0066] Generally, in regards to prosthesis 1 of FIG. 1, the deliverysystem includes an elongated outer sheath which supports the prosthesis1 in a compressed condition. The outer sheath is an elongated generallytubular structure which longitudinally surrounds the prosthesis 1. Theouter sheath has a diameter which is sufficiently small so as to bereadily inserted within a body lumen.

[0067] The deployment system may further include guidewires, multiplesheaths, dilation devices, i.e. balloons, nose caps and pushers, asknown in the art.

[0068] When the delivery system is positioned at the desired site in thebody lumen the outer sheath is retracted with respect to the prosthesis1. The retraction of the outer sheath progressively releases stent 2along its longitudinal (axial) extent and allows the stent 2 to radiallyexpand. As stent 2 further expands membrane 3, which is positionedwithin the stent 2, is deployed. Membrane 3 radially deploys by theradially expanding force of attached stent 2.

[0069] Prosthesis 40 as shown in FIG. 9 may be deployed using the samemethod as described above, and known in the art.

[0070] Deploying the above-described prosthesis in combination with agraft is a multi-step deployment process. The initial step is deployingthe first prosthesis including the stent and attached membrane asabove-described.

[0071] Generally, after the first prosthesis is positioned and deployedthen the tubular prosthesis is positioned and deployed using varioussystems as known in the art. For example, additional sheaths may beadded to the first delivery device, above-described, to deploy thetubular graft after deploying the first prosthesis. An example of amulti-stage delivery device which is useful for delivering the firstprosthesis and tubular prosthesis is described in U.S. Pat. No.6,123,723 to Konya, and is hereby incorporated herein by reference.Alternatively, second separate delivery system can be used to deploy thetubular prosthesis. After the initial prosthesis is deployed asdescribed above, an additional deployment device is used to position thetubular prosthesis within the graft receiving member of the membrane.Once the additional deployment device is in position the sheath isretracted allowing the tubular prosthesis to be placed within the graftreceiving member. The tubular prosthesis securably seals to the membraneby the blood flowing through the tubular prosthesis and forcing thetubular prosthesis to radially expand against the membrane.Additionally, stents may be deployed to secure the tubular prosthesis tothe arteries.

[0072] Similarly, a bifurcated system uses the same multi-step deliveryprocess, as above-described. Additional sheaths and/or deploymentdevices are used to deploy the tubular prosthesis as above-described.For example, FIG. 8 shows a bifurcated system where the tubularprosthesis are being implanted after the initial prosthesis 30 aincluding stent 32 a and attached membrane 33 a is deployed. The tubularprosthesis 38 a and 38 b are navigated to the abdomen. This would beaccomplished by mounting the tubular prosthesis 38 a and 38 b ontocatheters 36 and 39 and thereafter percutaneously inserting thecatheters into a femoral artery and navigating the tubular prosthesis tothe target site. Guidewires can be used to help delivery of the catheterto the target site. Navigating catheters within the human arterialsystem is well known in the art. An example of a balloon catheter isgiven in U.S. Pat. No. 5,304,197 issued to Pinchuck et al. on Apr. 19,1994, which is hereby incorporated herein by reference. The target siteis, as previously mentioned, through the graft receiving member 37 a and37 b of the membrane 33 a. The sheath of the catheter is removed,placing the tubular prosthesis 38 a and 38 b within the graft receivingmembers 37 a and 37 b. Removal of the catheter permits the blood to flowthrough the tubular prosthesis 38 a and 38 b further securing suchprosthesis 38 a and 38 b within the graft receiving members 37 a and 37b, and ultimately sealably securing the tubular prosthesis 38 a and 38 bto the stent 32 a. Distal anchoring stents (not shown) can be used tosecure the tubular prosthesis 38 a and 38 b to the walls of the iliacarteries. Distal anchoring stents can be mounted on and deployed usingthe same catheter as used delivering the tubular prosthesis 38 a and 38b. Alternatively, the anchoring stents can be deployed by using aseparate deployment device after placement of the tubular prosthesis 38a and 38 b has been completed.

[0073]FIG. 7 shows how the entire system looks after the bifurcatedprosthesis 30 including stent 32 and attached membrane 33, grafts 38 andanchoring stents 34 and 35 have been deployed.

[0074] The delivery of prosthesis 20 including a branched graft 28 ofFIG. 6 is similar to the delivery of prosthesis 30 of FIG. 8.

[0075] Initially the prosthesis 20 including stent 22 and attachedmembrane 23 are delivered to the desired sight as above-described. Asecond delivery system is used to implant the branched graft 28 in acompressed state within the graft receiving member 27 of the membrane23. Once in place the sheath is removed allowing graft 28 to expandwithin the graft receiving member 27, one leg 28 a of graft 28 is inplace and may be anchored with an anchoring stent 24. A third deliverydevice is used to properly position the other leg 28 b of the branchedgraft 28 and additionally add an anchoring stent 25 to secure the graftwithin the iliac artery 8 b. FIG. 6 shows how the entire system looksafter the prosthesis 20 including the branched graft 28 is deployed.

[0076] It may be desirable to have additional securement of theprosthesis to the aortic wall. Multiple prosthesis, as described above,can be used in combination to offer securement of the prosthesiscephalically to the renal arteries. For example, FIG. 11 shows amulti-component endovascular prosthesis 50 of the present inventionwhich includes a first expandable prosthesis 51, and second expandableprosthesis 61. The prosthesis, 51 and 61, are similar to the prosthesis1 in FIG. 1 including a stent, and a membrane extending traverselyacross the inner lumen and attached to the stent, and having one or moregraft receiving members. The first expandable prosthesis 51 and secondexpandable prosthesis 61 include an expandable stent (52, 62), and amembrane (53, 63) having graft receiving openings (57, 67),respectively. FIG. 11 shows the first expandable prosthesis 51 furtherincluding fluid flow opening 54 to provide an outlet for fluid to flowthrough the membrane 53. The fluid flow opening 54 includes a slit, ahole, a fluid penetrable material and the like. FIG. 11 shows abifurcated system including tubular grafts 58 (which includes 58 a and58 b) which extends sealably through each prosthesis, (51, 61) at thegraft receiving opening (57, 67) for directing fluid through the tubulargrafts 58. In addition, FIG. 11 shows grafts 58 including a porousportion 59 (which includes 59 a and 59 b) disposed on grafts 58 betweenthe first expandable prosthesis 51 and the second expandable prosthesis61 to allow for fluid exchange through the porous portion 59 of grafts58. The porous portion 59 includes a stent, slits, fluid permeablematerial and the like.

[0077] Deployment of prosthesis 50 is similar to those prosthesis asabove-described. For an abdominal aortic aneurysm application, the firstexpandable prosthesis 51 is positioned and deployed cephalic to therenal arteries 9 (includes 9 a and 9 b) via a delivery device in thesame manner as described above. The same delivery device usingadditional sheaths or a second delivery device is used to implant secondexpandable prosthesis 61 between the renal arteries 9 and the abdominalaneurysm. An additional delivery device is used to deliver grafts 58through the graft receiving opening (57, 67). Graft 58 a is extendedthrough graft receiving opening (57, 67) of each prosthesis (51, 61),respectively. Second graft 58 b is extended through graft receivingopening (57, 67). Grafts 58 a and 58 b are extended sealable through thegraft receiving openings (57,67) for directing fluid therethrough. Thesame deployment procedure as above-discussed is used to deliveryprosthesis 50, as known in the art.

[0078] A further embodiment of the present invention is an endovascularprosthesis 70 of FIG. 12, which is similar to prosthesis 1, of FIG. 1including a stent and a membrane. FIG. 12 shows the “M” shaped stent 72having an inner lumen 76, a distal end 74 and a proximal end 75. Thedistal end 74 has an opening and the proximal end 75 has two openingsopposed the distal opening. A puncturable membrane 73 extends acrosseach of the proximal end 75 openings for puncturably receiving a graft.The stent 72 of FIG. 12 is similar to the stents as above-described butis preferably a weave or braid of stent filaments. As shown in FIG. 13,a typical braided stent includes a first set of filaments 71L wound in afirst helical direction (to the left as shown in FIG. 13) and a secondset of filaments 71R wound in a second, opposite helical direction (tothe right as shown in FIG. 13), forming a plurality of overlaps 79.Filaments 71L and 71R may be wire, such as nitinol or stainless steel,or may comprise polymer or any type of filaments known in the art. Theprosthesis 70 may be a hybrid material having two materials woven orbonded together such as a PTFE and Dacron, where Dacron is bonded on theexterior of the PTFE.

[0079] As used herein, a “braided” stent refers to a stent formed of atleast two continuous filaments which are interwoven in a pattern, thusforming overlaps 79 as shown in FIG. 13. At each overlap, one filamentis positioned radially outward relative to the other filament. Followingeach filament along its helical path through a series of consecutiveoverlaps, that filament may, for example be in the radial inwardposition in one overlap and in the radial outward position in a nextoverlap, or may in the inward position for two overlaps and in theoutward position for the next two, and so on. Exemplary braided stentsare disclosed in U.S. Pat. No. 4,655,771 to Hans I. Wallsten, and isincorporated herein by referred. The endovascular prosthesis 70 mayinclude a stent-graft composite where the stent is an open structurewith a non-permeable graft material attached thereto. A stent-graftcomposite can further have a stent with one opening at the distal endand a crimped opening at the proximal end supporting a graft which formsthe two openings at the proximal end 75.

[0080] The endovascular prosthesis of FIG. 12 further includes apuncturable membrane 73 which is similar to membrane 3 of FIG. 1 asdescribed-above having weakened section, opening, slit, or hole forreceiving a graft therethrough. Membrane 73 is similarly attached tostent 72 as described above by mechanical, thermal, chemical, andadhesively attached. Membrane 73 and/or graft receiving opening 77 formsa fluid seal between the tubular prosthesis 78 and the stent 72 at theproximal end 75.

[0081] The endovascular prosthesis 70 of FIG. 12 is shown in combinationwith tubular prosthesis 78. Any number of tubular grafts may be useddepending on the application. FIG. 12 shows the tubular prosthesis 78extending through the distal end 74 opening of the prosthesis 70 andpuncturably through membrane 73 thereby forming a fluid seal between thetubular prosthesis 78 and the stent 72 at the proximal end 75. Bloodflow is directed through the tubular prosthesis 78. The tubularprosthesis 78 are positioned in each iliac artery so that the bloodexits the tubular prosthesis 78 into each iliac artery (8 a, 8 b).

[0082] The deployment of prosthesis 70 is similar to the manner ofdeployment described for prosthesis 1 of FIG. 1. Generally, the deliverysystem is positioned in the body lumen, and the outer sheath isretracted with respect to the prosthesis 70. The retraction of the outersheath progressively releases the stent 72 along its longitudinal(axial) extent and allows the stent 72 to radially expand. The membrane73, which is positioned across the stent lumen 76, is radially deployedby the radially expanding force of the attached stent 72.

[0083] Additionally, secondary delivery devices are used to deploytubular prosthesis 78 through the graft receiving membrane 77, similarto those above-described. The implanted bifurcated system is shown inFIG. 12.

[0084] A further embodiment of the present invention similar to FIG. 12is shown in FIG. 14 which provides for additional securement of theprosthesis cephalically to the renal arteries 9 (includes 9 a and 9 b).FIG. 14 shows an endovascular prosthesis 80 where a portion of theprosthesis 80 caudal to the renal arteries 9, similar to the embodiment70 of FIG. 12, has an “M” shaped configuration with an opening at oneend and two openings 84 at the opposed end. The endovascular prosthesis80 of FIG. 14 is a graft-stent composite including a stent 82, grafts 86and membranes 83. The stent 82 extends the full length of the prosthesis80 having a distal end 87, a proximal end 88 and an opening extendingtherethrough. As shown in FIG. 14, a portion of the endovascularprosthesis 80 cephalic to the renal arteries 9 includes a first graft 81which is attached to the distal end 87 of the stent 82 having an innerlumen therethrough. A portion of the prosthesis 80 caudal to the renalarteries 9 includes a second graft 86 which is attached to the proximalend 88 of the stent 82 and forms the “M” shape, similar to theprosthesis 80 of FIG. 14. The second graft 86 forms two smaller lumens84 within the stent 82 opening. Membrane 83 extends transversely acrosseach of the two lumens 84 of the second graft 86. Membrane 83 is similarto the construction materials as described for that of prosthesis 1 ofFIG. 1. Membrane 83 can be attached to graft 86, in the manner asabove-described, by adhesive bonding, such as silicone or polyurethane;mechanical attachment, such as sutures or staples; thermal bonding,laminate; or chemical bonding. The two grafts 81 and 86 are spaced apartto provide for blood exchange through the stent 82 and renal arteries 9.The section of the stent 82 between the first graft 81 and second graft86 may be an open celled structure or a covered stent which isblood-permeable. FIG. 14 shows the endovascular prosthesis 80 having awider cross-sectional area at distal end 87 and proximal end 88 wherethe stent 82 secures the prosthesis 80 to the artery wall, and a narrowcross-sectional area there between. One can appreciate that theendovascular prosthesis 80 may be one cross-sectional area throughoutthe length of the prosthesis 80 or varying cross-sectional areas as longas the two ends provide for securement to the artery wall and allow forundisturbed blood-flow therethrough.

[0085] Prosthesis 80 can be used in combination with a tubularprosthesis 89 as shown in FIG. 14. The tubular prosthesis 89 extendsthrough each of the respective membranes 83 and provides a sealableattachment between the graft 86 and the tubular prosthesis 89. The bloodis diverted into each tubular prosthesis 89. The tubular prosthesis 89is those known in the art and above-described in reference to theprosthesis 10 in FIG. 4.

[0086] To deploy the prosthesis 80, the prosthesis 80 is typicallycompressed into a radially compressed state into a delivery device, asknown in the art and above-described. The prosthesis 80 is thenintroduced to the lumen into which it is to be deployed, navigatedthrough the lumen to a deployment location, typically a diseased arterysuch as the aorta. The prosthesis 80 is expanded to a radially expandedstate in the deployment location as is known in the art. FIG. 14 showsthe prosthesis 80 deployed across the renal arties 9 a and 9 b where theopen-cell structure or porous portion of the prosthesis 80 is betweenthe renal arteries 9 a and 9 b. The deployment of the tubular prosthesis89 (89 a and 89 b) of the present invention is thus deployed by a methodsimilar to that described above using a separate delivery device or thesame delivery device with additional sheaths or stages, as known in theart. The tubular prosthesis 89 are puncturably delivered through themembrane 83. The tubular prosthesis are sealably secured to the graft 86by the outward force from the blood flowing there through and therestricted size of the lumens 84.

[0087] Another embodiment of the present invention which is similar toprosthesis 1 of FIG. 1 but instead of using a membrane to sealablesecure a tubular prosthesis to the stent, a foam 93 is used to securelyattaching the tubular prosthesis 98 to the stent 92 as shown in FIG. 15.The endoprosthesis 90 of FIG. 15 includes a stent 92, and a tubularprosthesis 98 having an expanded foam 93 attached thereto. The stent 92is similar to those described above being an expandable stent 92 havinga distal end, a proximal end and an inner lumen. As shown in FIG. 16,stent 92 has an inner surface 94 and an outer surface. The tubularprosthesis 98 is similar to those described above having an interiorsurface and exterior surface 99. The expanded foam 93 is attached to theexterior surface 99 of the tubular prosthesis 98. The tubular prosthesis98 is placed within the lumen 91 of the stent 92 and the expanded foam93 sealably secures the tubular prosthesis 98 to the stent 92.

[0088] The expandable foam 93 must be biocompatible and requisitestrength characteristics. The foam is similar to those known in the artsuch as gelatin sponge, collagen sponge, cellulose sponge, hyaluronicacid and foams used for nasal surgery. The expandable foam 93 may beporous or non-porous. The expandable foam 93 is provided in a compressedstate prior to placement within the stent 92. Once in place, theexpandable foam 93 is allowed to expand into the matrix of stent 92 tosecurably attach the tubular prosthesis 98 in the stent lumen 91. Someexpandable foams are non-permeable upon implantation, while othersprovide a scaffold structure for clot formation. Some scaffold structurefoams may dissolve over time leaving a sealable clot formation. Suitableavailable commercial foams include Spongostern, Surgifoam, (Ferrosan,distributed by Johnson & Johnson); Gelfoam (Pharmacia & UpJohn Company);Avitene Ultrofoam (Bard/Davol); MeroGel Nasal Dressing, Sinus Stent andOtologic Packing, HYAFF (Medtronic Xomed, Jacksonville, Fla.).

[0089] The expandable foam 93 is attached to the outer surface 99 of thetubular prosthesis 98 by mechanical, adhesive, thermal, or chemicalattachment. As shown in FIG. 16, the foam 93 covered graft 98 is placedinto the lumen 91 of the stent 92 and the expandable foam 93 is allowedto expand by either a reaction in the vascular environment, such ashydrolysis, or by removing an outside force, such as sheath. Theexpandable foam 93 expands against and into the structure of the stent92 securing the tubular prosthesis 98 in place in a sealable manner. Asshown in FIG. 16 one or more tubular prosthesis 98 can be used dependingon the application.

[0090] Additionally, as shown in FIG. 17, the expandable foam 93 coveredtubular prosthesis 98 of FIG. 16 can be used in combination with theprosthesis 1 of FIG. 1. Prosthesis 90 a includes a stent 92 a and amembrane 97 having a graft receiving member 97 a, similar to prosthesis1 of FIG. 1. The expandable foam 93 a covered tubular prosthesis 98 a isextended through the graft receiving member 97 a. The expandable foam 93a expands within the graft receiving member 97 a to provide a sealablesecurement of the tubular prosthesis 98 a to the membrane 97, as shownin FIG. 17.

[0091] Further the embodiment of the present invention is a kit of partsfor assembly into an endovascular prosthetic system. The kit includes anexpandable stent 92 and a tubular prosthesis 98. The expandable stent 92has a distal end, a proximal end and an inner lumen 91 for insertioninto a body endovascularly. The tubular prosthesis 98 is adapted to beinserted within the inner lumen 91 of the stent 92. The tubularprosthesis 98 has an interior surface for body fluid flow and anexterior surface. Additionally, an expandable foam 93 is attached to theexterior surface of the tubular prosthesis 98. The expandable foam 93 isadapted to expand within the stent 92 to sealably secure the tubularprosthesis 98 to the stent 92.

[0092] Deploying prosthesis 90 is similar to the method of deployingprosthesis 30 of FIG. 7. The prosthesis 90 is a multi-step process asabove-discussed. The stent 92 is typically compressed into a radiallycompressed state into a delivery device, as known in the art. The stent92 is then introduced into the lumen in which it is to be deployed,navigated through the lumen to a deployment location, and then expandedto a radially expanded state in the deployment location, as is known inthe art. The expandable foam 93 covered tubular prosthesis 98 are alsocompressed into a radially compressed state into a delivery device. Oncethe tubular prosthesis 98 are positioned within the stent lumen 91 thetubular prosthesis 98 are deployed by removing a restraining element,such as a sheath, of the delivery device. The expandable foam 93 isallowed to expand filling the space within the stent lumen 91, into thestructure of the stent 92, and sealably securing the tubular prosthesis98 within the stent 92. As above-discussed separate delivery devices maybe used to deploy each component of the prosthesis 90 or a multi-stepdelivery device may be used.

[0093] In addition, prosthesis 90 a of FIG. 17 is deployed using thesame delivery system as above-described for prosthesis 90 of FIG. 16,except the stent 92 of FIG. 16 is substituted with the first prosthesis91 a. Initially, first prosthesis 91 a is compressed in a deliverydevice, delivered to the target site within the lumen and allowed todeploy at the site. The expandable foam 93 a covered tubular prosthesis98 a are delivered via the delivery device in a compressed state intothe graft receiving member 97 a. After placing the delivery devicewithin the graft receiving members 97 a at the desired location, thedelivery device is removed to allow the expandable foam 93 a to expandwithin the graft receiving members 97 a. The expandable foam 93 a incombination with the graft receiving members 97 a sealably secure thetubular prosthesis 98 a to the first prosthesis 91 a.

[0094] A further embodiment of the present invention is an endovascularprosthetic assembly 100 as shown in FIGS. 18 and 19 which is similar tothe prosthesis 90 of FIG. 15 but instead of using an expandable foam onthe grafts to secure the grafts to the stent, a polymeric material 130is used. FIG. 19 shows the endovascular prosthetic assembly 100including a stent 120 and a tubular prosthesis 180 similar to thosedescribed above. Endovascular prosthetic assembly 100 further includes apolymeric material 130 sealably supporting the tubular prosthesis 180 tothe stent 120. The polymeric material 130 is a substantially homogenousreaction product of monomer materials which is formed in situ. As shownin FIG. 18, the exterior surface of the tubular prosthesis 180 and innersurface of the lumen of the stent 120 are pre-coated with a primaryreactive material 110. The tubular prosthesis 180 is positioned withinthe inner lumen of the stent 120. A secondary material (not shown)reactive with the primary material 110 is introduced in the vicinity oftubular prosthesis 180 and the inner lumen of the stent 120. The primarymaterial 110 and secondary material react forming a polymeric material130 which sealably supports the tubular prosthesis 180 to the stent 120.

[0095] In general, the polymeric material 130 is biocompatible, slightlythrombotic, and non-toxic. The polymeric material 130 can be a foam orhydrogel. A hydrogel which is useful is one formed from the mixture of apolymer and monomer and an reaction promoter such as a chemicalactivator or light activator (focal therapeutic). Examples of suitablematerials which react to form a hydrogel include polyethylene glycol andiron, or polyethylene glycol and peroxide in addition to lightactivation or a chemical activator. For additional suitable hydrogel andmethods of preparation, refer to U.S. Pat. No. 6,379,373 to Sawhney,which is hereby incorporated herein by reference.

[0096] In addition, one or more tubular prosthesis 180 can be useddepending on the application. The prosthesis 100 can be offered in a kitform. The kit of parts for assembly into an endovascular prostheticsystem 100 includes a stent 120, a primary reactive material 110, atubular prosthesis 180, and a secondary reactive material. The stent 120has an inner surface, an outer surface and an inner lumen. The primaryreactive material 110 is disposed on said inner surface of the stent120. The tubular prosthesis 180 is adapted to extend within the innerlumen of the stent 120. The tubular prosthesis 180 has an interiorsurface and an exterior surface, and the primary material 110 isdisposed on said exterior surface of the tubular prosthesis 180. Thesecondary material is reactive with the primary material 110 and adaptedto be applied to the primary material 110 upon insertion of the tubularprosthesis 180 within the inner lumen of the stent 180. The secondarymaterial is reactive with the primary material 110 to form a sealbetween the tubular prosthesis 180 and the stent 120.

[0097] Deploying prosthesis 100 is similar to the deployment process ofprosthesis 90 of FIG. 15. The prosthesis 100 is also a multiple stepprocess as above-discussed. The stent 120 is compressed into a radiallycompressed state into a delivery device, as known in the art. The stent120 is then introduced to the lumen into which it is to be deployed,navigated through the lumen to a deployment location, and then expandedto a radially expanded state in the deployment location, as is known inthe art. Secondarily, the tubular prosthesis 180 are compressed in aradially compressed state within a delivery device. The tubularprosthesis 180 are positioned within the lumen of the stent 120. Thetubular prosthesis 180 are partially deployed by removing the sheath ordelivery device around the portion of the tubular prosthesis 180 whichis positioned within the lumen of the stent 120. A secondary material isinjected into the vicinity of the tubular prosthesis 180 and stent 120.The secondary material is allowed to react with the primary material 110on the exterior surface of the tubular prosthesis 180 and the interiorsurface of the stent 120. The polymeric reaction product 130 from thetwo materials sealably secures the tubular prosthesis 180 to the stent120. As above discussed separate delivery devices may be used to deployeach component of the prosthesis 100 or a multi-step delivery device maybe used, as known in the art.

[0098] In addition, combining the technology as shown in FIGS. 18 and 19with the prosthesis 1 of FIG. 1, provides prosthesis 200 as shown inFIGS. 20 and 21. In this combination, the membrane 230 and the tubularprosthesis 280 are pretreated with the primary material 210, asdescribed above. FIG. 20 shows tubular prosthesis 280 is placed withinthe stent lumen through the graft receiving member 270 of the membrane230. A secondary material is introduced which reacts with the primarymaterial 210 on the tubular prosthesis 280 and the membrane 230. Apolymeric material 240 is formed which sealably secures the tubularprosthesis 280 to the stent 220, as shown in FIG. 21.

[0099] Prosthesis 200 is deployed in the same manner as discussed forprosthesis 100 of FIG. 18, except stent 120 is replaced with a firstprosthesis 219 including a stent 220 and a membrane 230, attached to thestent 220, having graft receiving member 270. The first prosthesis 219is deployed at the target site using a delivery device as abovedescribed. The tubular prosthesis 280 is compressed in a delivery deviceand then positioned through the graft receiving members 270. The tubularprosthesis 280 is deployed within the graft receiving members 270. Asecondary reactive material is introduced in the vicinity of themembrane 230 and the tubular prosthesis 280. The secondary reactivematerial is allowed to react with the primary material 210 on thetubular prosthesis 280 and the membrane 230. The reaction product 240results in a polymeric material which sealably secures the tubularprosthesis 280 to the membrane 230. Variations on this method may beused according to the known art.

[0100] Having described particular arrangements of the present inventionherein, it should be appreciated by those skilled in the art thatmodifications may be made thereto without departing from thecontemplated scope thereof. Accordingly, the arrangements describedherein are intended to be illustrative rather than limiting, the truescope of the invention being set forth in the claims appended hereto.

What is claimed is:
 1. An endovascular prosthesis comprising: (a) anexpandable stent having a distal end, a proximal end and an inner lumen;and (b) a membrane supported by said stent and extending across saidlumen, said membrane including a graft receiving member for sealablyreceiving at least one tubular graft therethrough.
 2. An endovascularprosthesis of claim 1, wherein said graft receiving member comprises aslit.
 3. An endovascular prosthesis of claim 2, wherein said graftreceiving member is electrostatically spun material.
 4. An endovascularprosthesis of claim 1, wherein said graft receiving member comprises avalve.
 5. An endovascular prosthesis of claim 1, wherein said graftreceiving member comprises a weakened section.
 6. An endovascularprosthesis of claim 1, wherein said graft receiving member comprises apenetrable material.
 7. An endovascular prosthesis of claim 1, furthercomprising a second graft receiving member.
 8. In combination, anendovascular prosthesis of claim 1, and a tubular graft extendingsealably through said graft receiving member.
 9. The combination ofclaim 8, wherein said tubular graft has an interior surface and exteriorsurface, and an expandable foam on said exterior surface, said foambeing expandable within said graft receiving member, sealably securingsaid tubular graft to said graft receiving member.
 10. An endovascularprosthesis of claim 8, further comprising a polymeric material sealablysecuring said tubular graft to said membrane.
 11. A method of forming anendovascular prosthesis comprising the steps of: a. providing anexpandable stent defining a lumen therein comprising distal end and aproximal end; b. providing a membrane including a graft receiving memberfor sealably receiving at least one tubular graft therethrough; and c.attaching said membrane to said stent, wherein said membrane extendsacross said lumen and is supported thereby.
 12. A method of implantingan endovascular prosthesis within a vessel comprising: a. providing, ina compressed first diameter, a radially expandable stent having a distalend, a proximal end and an inner lumen; and a membrane supported by saidstent and extending across said lumen, said membrane including a graftreceiving member for sealably receiving at least one tubular grafttherethrough; b. delivering said stent within a vessel to an area ofimplantation; and c. permitting said stent to radially expand to asecond diameter; and thereby engage a vessel wall.
 13. A bifurcatedendovascular prosthesis comprising: (a) a first prosthetic componentcomprising: (i) an expandable stent having a distal end, a proximal endand an inner lumen; and (ii) a membrane extending transversely acrosssaid inner lumen and attached to said stent, said membrane having anopening; and (b) a second prosthetic component extending into saidopening in a substantially fluid tight seal, said second componentcomprising a branched graft.
 14. A bifurcated endovascular prosthesis ofclaim 13, wherein said membrane has a first opening and a secondopening.
 15. A bifurcated endovascular prosthesis of claim 14, whereinsaid branched graft comprises a first graft extending into said firstopening, and a second graft extending into said second opening in asubstantially fluid-tight seal.
 16. A bifurcated endovascular prosthesisof claim 15, wherein said membrane comprises polyurethane, polyethylene,polytetrafluoroethylene, and combinations thereof.
 17. A bifurcatedendovascular prosthesis of claim 15, wherein said first opening andsecond opening each comprises a valve.
 18. A bifurcated endovascularprosthesis of claim 15, wherein said first prosthetic component isadapted to reside in an aortic artery, and said first graft and secondgraft are each adapted to respectively reside in separate iliacarteries.
 19. A method of forming a bifurcated endovascular prosthesiscomprising the steps of: a. providing a first prosthetic componentcomprising: (i) an expandable stent having a distal end, a proximal endand an inner lumen; and (ii) a membrane extending transversely acrosssaid inner lumen and attached to said stent, said membrane having anopening; b. providing a second prosthetic component comprising abranched graft; and c. extending said second prosthetic component intosaid opening of said membrane, wherein said membrane forms asubstantially fluid tight seal with said second component.
 20. A methodof implanting a bifurcated endovascular prosthesis within a vesselcomprising: a. providing, in a compressed first diameter, a firstprosthetic component comprising an expandable stent having a distal end,a proximal end and an inner lumen; and a membrane extending transverselyacross said inner lumen and attached to said stent, said membrane havingan opening; b. providing a second prosthetic component comprising abranched graft; c. delivering said first prosthetic component within avessel to an area of implantation; d. permitting said first prostheticcomponent to radially expand to a second diameter; and thereby engage avessel wall; and e. delivering said second prosthetic component withinsaid opening of said stent forming a substantially fluid tight sealbetween said membrane and said second prosthetic component.
 21. A methodof forming a bifurcated endovascular prosthesis comprising the steps of:a. providing a prosthetic component comprising: (i) an expandable stenthaving a distal end, a proximal end and an inner lumen; and (ii) amembrane extending transversely across said inner lumen and attached tosaid stent, said membrane having a first opening and a second opening;b. providing a first graft having a first inner surface, a first outersurface defining a first interior lumen; c. providing a second grafthaving a second inner surface, a second outer surface defining a secondinterior lumen; d. extending said first graft into said first opening ofsaid membrane, wherein said membrane forms a substantially fluid tightseal between said prosthetic component and said first graft; and e.extending said second graft into said second opening of said membrane,wherein said membrane forms a substantially fluid tight seal betweensaid prosthetic component and said second graft.
 22. A method ofimplanting a bifurcated endovascular prosthesis within a vesselcomprising: a. providing, in a compressed first diameter, a prostheticcomponent comprising an expandable stent having a distal end, a proximalend and an inner lumen; and a membrane extending transversely acrosssaid inner lumen and attached to said stent, said membrane having anopening; b. providing a first graft having a first inner surface, afirst outer surface defining a first interior lumen; c. providing asecond graft having a second inner surface, a second outer surfacedefining a second interior lumen; d. delivering said prostheticcomponent within a vessel to an area of implantation; e. permitting saidprosthetic component to radially expand to a second diameter; andthereby engage a vessel wall; f. delivering said first graft within saidopening of said stent forming a substantially fluid tight seal betweensaid membrane and said first graft; and g. delivering said second graftwithin said opening of said stent forming a substantially fluid tightseal between said membrane and said second graft.
 23. An endovascularprosthesis comprising: (a) an expandable stent having an inner lumen, afirst end and a second end; and (b) a membrane attached to said stentextending transversely across said lumen, said membrane comprisingelectrostatically spun material having a graft receiving opening forsealably receiving at least one tubular graft therethrough.
 24. Incombination, an endovascular prosthesis of claim 23, and at least onetubular prosthesis extending through said graft receiving opening andsealably supporting said at least one tubular prosthesis.
 25. A methodof forming an endovascular prosthesis comprising the steps of: a.providing an expandable stent having an inner lumen, a first end and asecond end; b. providing a membrane comprising electrostatically spunmaterial having a graft receiving opening for sealably receiving atleast one tubular graft therethrough; and c. attaching said membrane tosaid stent, wherein said membrane extends transversely across said lumenand is supported thereby.
 26. A method of implanting an endovascularprosthesis within a vessel comprising: a. providing, in a compressedfirst diameter, an expandable stent having a first end, a second end andan inner lumen; and a membrane comprising electrostatically spunmaterial supported by said stent and extending across said lumen, saidmembrane including a graft receiving opening for sealably receiving atleast one tubular graft therethrough; b. delivering said stent within avessel to an area of implantation; and c. permitting said stent toradially expand to a second diameter; and thereby engage a vessel wall.27. A multi-component endovascular prosthetic system comprising: (a) afirst expandable prosthesis comprising: (i) a first expandable stenthaving a distal end, a proximal end and an inner lumen; and (ii) a firstmembrane extending transversely across said inner lumen and attached tosaid first stent, said first membrane having a first graft receivingopening; (b) a second expandable prosthesis spaced from said firstprosthesis comprising: (i) a second expandable stent having a distalend, a proximal end and an inner lumen; and (ii) a second membraneextending transversely across said inner lumen and attached to saidsecond stent, said second membrane having a second graft receivingopening; and (c) a tubular graft extending sealably through said firstgraft receiving opening and said second graft receiving opening fordirecting fluid through said tubular graft.
 28. A multi-componentendovascular prosthetic system of claim 27, wherein said tubular grafthas a porous portion disposed between said first expandable prosthesisand said second expandable prosthesis to allow for fluid flow throughsaid porous portion.
 29. A multi-component endovascular prostheticsystem of claim 28, wherein said porous portion comprises a stent.
 30. Amulti-component endovascular prosthetic system of claim 28, wherein saidporous portion comprises slits.
 31. A multi-component endovascularprosthetic system of claim 28, wherein said porous portion comprisesfluid permeable material.
 32. A multi-component endovascular prostheticsystem of claim 27, wherein said first membrane has a pair of firstgraft receiving openings, said graft receiving openings each receiving atubular graft therethrough.
 33. A multi-component endovascularprosthetic system of claim 32, wherein said first membrane has a fluidflow opening.
 34. A multi-component endovascular prosthetic system ofclaim 33, wherein said second membrane has a pair of second graftreceiving openings, said second graft receiving openings each receivinga tubular graft therethrough.
 35. A method of forming a multi-componentendovascular prosthesis comprising the steps of: a. providing a firstexpandable prosthesis comprising: (i) a first expandable stent having adistal end, a proximal end and an inner lumen; and (ii) a first membraneextending transversely across said inner lumen and attached to saidfirst stent, said first membrane having a first graft receiving opening;b. providing a second expandable prosthesis spaced from said firstprosthesis comprising: (i) a second expandable stent having a distalend, a proximal end and an inner lumen; and (ii) a second membraneextending transversely across said inner lumen and attached to saidsecond stent, said second membrane having a second graft receivingopening; and c. providing a tubular graft having an outer surface, andan inner surface defining an inner lumen; and d. extending said tubulargraft through said first graft receiving opening and said second graftreceiving opening for directing fluid through.
 36. A method ofimplanting a multi-component endovascular prosthesis within a vesselcomprising: a. providing, in a compressed first diameter, a firstexpandable prosthesis comprising a first expandable stent having adistal end, a proximal end and an inner lumen; and a first membraneextending transversely across said inner lumen and attached to saidfirst stent, said first membrane having a first receiving opening; b.providing, in a compressed second diameter, a second expandableprosthesis comprising a second expandable stent having a distal end, aproximal end and an inner lumen; and a second membrane extendingtransversely across said inner lumen and attached to said second stent,said second membrane having a second receiving opening; c. providing atubular graft having an outer surface, and an inner surface defining agraft inner lumen; d. delivering said first expandable prosthesis withina vessel to an area of implantation; e. permitting said first expandableprosthesis to radially expand to a third diameter; and thereby engage avessel wall; f. delivering said second expandable prosthesis spaced fromsaid first expandable prosthesis within a vessel to an area ofimplantation; g. permitting said second expandable prosthesis toradially expand to a fourth diameter; and thereby engage a vessel wall;h. delivering said tubular graft within said first receiving opening andsaid second receiving opening forming a substantially fluid tight sealbetween said first membrane and said tubular graft, and said secondmembrane and said tubular graft.
 37. An endovascular prosthesiscomprising: (a) a stent having an inner lumen, a distal end and aproximal end, said distal end having an opening, and said proximal endhaving two openings opposing said distal opening; and (b) a puncturablemembrane extending across each of said proximal end openings.
 38. Incombination, an endovascular prosthesis of claim 37, and at least onetubular graft extending through said distal end opening and puncturablythrough one of said membranes at said proximal end, thereby forming afluid seal between said tubular graft and said stent at said proximalend.
 39. The combination of claim 38, further comprising a pair oftubular grafts extending through said distal end, with one tubular graftextending puncturably through each membrane at said proximal end of saidstent to thereby form a fluid seal between said tubular graft and saidstent at said proximal end.
 40. A method of forming an endovascularprosthesis comprising the steps of: a. providing an expandable stenthaving an inner lumen, a distal end and a proximal end, wherein saiddistal end having an opening and said proximal end having two openingsopposing said distal opening; b. providing a puncturable membrane; andc. attaching said membrane to said stent transversely across each ofsaid proximal end openings.
 41. A method of implanting an endovascularprosthesis within a vessel comprising: a. providing, in a compressedfirst diameter, an expandable stent having a distal end, a proximal endand an inner lumen, wherein said distal end having an opening and saidproximal end having two openings opposing said distal opening; and apuncturable membrane supported by said stent and extending across saidlumen; b. delivering said stent within a vessel to an area ofimplantation; and c. permitting said stent to radially expand to asecond diameter; and thereby engage a vessel wall.
 42. An endovascularprosthesis comprising: (a) an expandable stent having a distal end, aproximal end, and an opening extending therethrough; (b) a first graftattached to said distal end of said stent within said opening, andhaving an inner lumen extending therethrough; (c) a second graftattached to said proximal end of said stent within said opening andspaced from said first graft, said second graft having at least twoinner lumens extending therethrough; and (d) a membrane extendingtransversely across each of said inner lumens of said second graft. 43.In combination, an endovascular prosthesis of claim 42, and at least twotubular prosthesis, one of such prosthesis extending puncturably througheach of said respective membranes.
 44. A method of forming anendovascular prosthesis comprising the steps of: a. providing anexpandable stent having a distal end and a proximal end, and an openingextending therethrough; b. providing a first graft having an inner lumenextending therethrough; c. providing a second graft having at least twoinner lumens extending therethrough; d. providing a membrane; e.attaching said first graft to said distal end of said stent within saidopening; f. attaching said second graft to said proximal end of saidstent within said opening and spaced from said first graft; and g.attaching said membrane transversely across each of said inner lumens ofsaid second graft.
 45. A method of implanting an endovascular prosthesiswithin a vessel comprising: a. providing, in a compressed firstdiameter, an expandable stent having a distal end, a proximal end and anopening therethrough, said stent comprising a first graft attached tosaid distal end of said stent within said opening, and having an innerlumen extending therethrough; a second graft attached to said proximalend of said stent within said opening and spaced from said first graft,said second graft having at least two inner lumens extendingtherethrough; and a membrane extending transversely across each of saidinner lumens of said second graft; b. delivering said stent within avessel to an area of implantation; and c. permitting said stent toradially expand to a second diameter; and thereby engage a vessel wall.46. An endovascular prosthetic assembly comprising: (a) an expandablestent having a distal end, a proximal end and an inner lumen having aninner surface and an outer surface; (b) a tubular graft inserted withinsaid inner lumen, said tubular graft having an interior surface andexterior surface; and (c) an expanded foam attached to said exteriorsurface of said graft, said expanded foam sealably securing said tubulargraft to said stent.
 47. An endovascular prosthesis of claim 46, whereinsaid expanded foam is adhesively bonded to said exterior surface of saidgraft.
 48. An endovascular prosthesis of claim 46, wherein said expandedfoam is mechanically fastened to said exterior surface of said graft.49. An endovascular prosthesis of claim 46, further comprising a secondtubular graft inserted within said inner lumen, said second tubulargraft having a second interior surface and a second exterior surface,and a second expanded foam bonded to said second exterior surface, saidsecond expanded foam sealably securing said second tubular graft to saidstent.
 50. A kit of parts for assembly into an endovascular prostheticsystem, comprising: (a) an expandable stent having a distal end, aproximal end and an inner lumen for insertion into a bodyendovascularly; (b) a tubular graft adapted to be inserted within saidinner lumen, said tubular graft having an interior surface for bodyfluid flow and an exterior surface; and (c) an expandable foam on saidexterior surface of said tubular graft, said expandable foam adapted toexpand within said stent to sealably secure said tubular graft to saidstent.
 51. A method of forming an endovascular prosthesis comprising thesteps of: a. providing an expandable stent having a distal end, aproximal end and an inner lumen having an inner surface and an outersurface; b. providing a tubular graft having an interior surface andexterior surface; c. providing an expandable foam; d. attaching saidexpandable foam to said exterior surface of said graft; e. insertingsaid tubular graft within said inner lumen of said stent, wherein saidexpandable foam is in a compressed state; and f. allowing saidexpandable foam to expand within said stent and sealably securing saidtubular graft within said stent.
 52. A method of implanting anendovascular prosthesis within a vessel comprising: a. providing, in acompressed first diameter, an expandable stent having a distal end, aproximal end, an inner surface, an outer surface and an inner lumen; b.providing a tubular graft having an interior surface and an exteriorsurface, said tubular graft having, in a compressed second diameter, anexpandable foam attached to said exterior surface of said graft; c.delivering said stent within a vessel to an area of implantation; d.permitting said stent to radially expand to a third diameter; andthereby engage a vessel wall; e. delivering said graft within said innerlumen of said stent; and f. permitting said foam of said graft to expandto a fourth diameter, thereby sealably securing said graft to saidstent.
 53. An endovascular prosthetic assembly comprising: (a) a stenthaving an inner surface and an outer surface; (b) a tubular graftextending within said inner lumen, said tubular graft having an interiorsurface and an exterior surface, and an opening therethrough; and (c) apolymeric material sealably supporting said tubular graft to said stent.54. An endovascular prosthetic assembly of claim 53 wherein saidpolymeric material is a hydrogel.
 55. An endovascular prosthesis ofclaim 53, further comprising a second tubular graft extending withinsaid inner lumen, said second tubular graft having an interior surfaceand an exterior surface, and an opening therethrough; and said polymericmaterial sealably supporting said second tubular graft to said stent.56. A kit of parts for assembly into an endovascular prosthetic systemcomprising: (a) a stent having an inner surface, an outer surface and aninner lumen, a primary reactive material being disposed on said innersurface; (b) a tubular graft adapted to extend within said inner lumen,said graft having an interior surface and an exterior surface, saidprimary material being disposed on said exterior surface; and (c) asecondary material reactive with said primary material and adapted to beapplied to said primary material upon insertion of said graft withinsaid inner lumen, said secondary material being reactive with saidprimary material to form a seal between said graft and said stent.
 57. Amethod of forming an endovascular prosthesis comprising the steps of: a.providing a stent having an inner surface, an outer surface and an innerlumen; b. providing a tubular graft having an interior surface and anexterior surface, and an opening therethrough; c. providing a primarymaterial; d. providing a secondary material reactive with said primarymaterial; b. disposing said primary material on said inner surface ofsaid stent; e. disposing said primary material on said exterior surfaceof said tubular graft; f. inserting said tubular graft within said innerlumen of said stent; and g. introducing said secondary material intosaid inner lumen of said stent, wherein said secondary material reactwith said primary material defining a polymeric material sealablysupporting said tubular graft to said stent.
 58. A method of implantingan endovascular prosthesis within a vessel comprising: a. providing, ina compressed first diameter, an expandable stent having an innersurface, an outer surface and an inner lumen therethrough, said innersurface of said stent having a primary material disposed about saidsurface; b. providing a tubular graft having an interior surface and anexterior surface, said exterior surface of said graft having a primarymaterial disposed about said surface; c. providing a secondary materialreactive with said primary material; d. delivering said stent within avessel to an area of implantation; e. permitting said stent to radiallyexpand to a second diameter; and thereby engage a vessel wall; f.delivering said graft within said inner lumen of said stent; g.delivering said second material into said inner lumen of said stent; andh. permitting said secondary material to react with said primarymaterial defining a polymeric material sealably supporting said tubulargraft to said stent.
 59. An endovascular prosthesis comprising: (a) anexpandable stent having a distal end, a proximal end and an inner lumen;and (b) means for sealably attaching a tubular graft to said stentwithin said lumen.
 60. An endovascular prosthesis of claim 59, whereinsaid means comprises a membrane supported by said stent and extendingacross said lumen, said membrane including a graft receiving member forsealably receiving at least one tubular graft therethrough.
 61. Anendovascular prosthesis of claim 59, wherein said means comprises anexpandable foam bonded to said tubular graft.
 62. An endovascularprosthesis of claim 59, wherein said means comprises a polymericmaterial, said polymeric material comprising the reaction product of aprimary material on said inner lumen of said stent and on said tubulargraft, and a secondary material thereby forming a sealed attachmentbetween said tubular graft and said stent.